Halide perovskite thin films and methods for production thereof

Abstract

Methods are provided for making halide perovskite thin films. The method may include forming a pattern of islands of a nucleation promoter material onto a substrate; applying onto the substrate and islands a solution which includes a halide perovskite or precursors thereof, to form a coated substrate; and drying the coated substrate to form a crystalline halide perovskite film. Halide perovskite thin films, which may be made by these methods, and LEDs including these films are also provided.

We claim: 
     
       1. A method of making a halide perovskite thin film comprising:
 a) forming a pattern of islands of a nucleation promoter material directly onto a substrate; 
 b) applying onto the substrate and islands a solution which comprises a halide perovskite or precursors thereof, to form a coated substrate; and 
 c) drying the coated substrate to form a crystalline halide perovskite thin film, 
 wherein the applying and drying of the coated substrate are carried out in a manner effective to cause halide perovskite crystals to nucleate on the islands of the nucleation promoter material and grow such that neighboring crystals meet and merge into a continuous film. 
 
     
     
       2. The method of  claim 1 , wherein the substrate comprises silicon oxide glass or indium tin oxide glass. 
     
     
       3. The method of  claim 1 , wherein each of the islands has a diameter of from about 1 μm to about 10 μm. 
     
     
       4. The method of  claim 1 , wherein the pattern of islands is a grid pattern. 
     
     
       5. The method of  claim 1 , wherein the pattern of islands has a pitch size of from about 10 μm to about 100 μm. 
     
     
       6. The method of  claim 1 , wherein the pattern of islands has a pitch size, and wherein the crystalline halide perovskite thin film comprises halide perovskite crystals having a diameter of about the pitch size of the pattern of islands. 
     
     
       7. The method of  claim 1 , wherein the nucleation promoter material comprises a metal or a metal oxide. 
     
     
       8. The method of  claim 1 , wherein the nucleation promoter material is gold. 
     
     
       9. The method of  claim 1 , wherein the crystalline halide perovskite thin film comprises halide perovskite crystals having a diameter or largest dimension of from about 10 μm to about 100 μm. 
     
     
       10. The method of  claim 1 , wherein the halide perovskite crystals have a height or thickness from about 600 nm to about 700 nm. 
     
     
       11. The method of  claim 1 , wherein the halide perovskite comprises MAPbBr 3 , MAPbI 3 , or CsPbBr 3 . 
     
     
       12. A halide perovskite thin film structure comprising:
 a substrate; 
 a pattern of islands of a nucleation promoter material disposed directly on the substrate; and 
 halide perovskite crystals disposed on the substrate and the islands, the halide perovskite crystals being contiguously disposed in the form of a film, 
 wherein the halide perovskite crystals are characterized by periodical grains emanating from each of the islands of nucleation promoter material. 
 
     
     
       13. The thin film of  claim 12 , wherein the substrate comprises silicon oxide glass, indium tin oxide glass, or another suitable glass. 
     
     
       14. The thin film of  claim 12 , wherein each of the islands has a diameter of from about 1 μm to about 10 μm. 
     
     
       15. The thin film of  claim 12 , wherein the nucleation promoter material comprises a metal or a metal oxide. 
     
     
       16. The thin film of  claim 12 , wherein the nucleation promoter material is gold. 
     
     
       17. The thin film of  claim 12 , wherein the pattern of islands has a pitch size, and wherein the crystalline halide perovskite thin film comprises halide perovskite crystals having a diameter of about the pitch size of the pattern of islands. 
     
     
       18. The thin film of  claim 12 , wherein the crystalline halide perovskite thin film comprises halide perovskite crystals having a diameter or largest dimension of from about 10 μm to about 100 μm. 
     
     
       19. The thin film of  claim 12 , wherein the halide perovskite crystals have a thickness or height from about 600 nm to about 700 nm. 
     
     
       20. The thin film of  claim 12 , wherein the halide perovskite comprises MAPbBr 3 , MAPbI 3 , or CsPbBr 3 . 
     
     
       21. An LED comprising:
 an ITO bottom electrode; 
 a light-emitting layer comprising the thin film structure of  claim 12 ; and 
 a top electrode. 
 
     
     
       22. The LED of  claim 21 , wherein the top electrode comprises indium gallium eutectic. 
     
     
       23. The LED of  claim 21 , wherein the halide perovskite comprises MAPbBr 3 , MAPbI 3 , or CsPbBr 3 .